Figure 4

Histopathological changes in brain of control mice (n = 4) and of mice infected with 4 × 103PFU of DENV-3 (n = 4) by intracranial route, 6 days p.i. Hematoxilin & eosin-stained sections from cerebrum of a control animal with normal histological appearance of cerebrum (A) and hippocampus (E). Brain sections from a DENV-3-infected animal showing: meningoencephalitis characterized by infiltration of immune cells in the meninges (open arrow) (B), perivascular cuffing (PC) (C), gliosis (insert) and (D) vasculitis (asterisk). Note intense neuronal destruction in the pyramidal layer of the CA3 and CA2 areas of the hippocampus (F). Immunohistochemical staining for anti-NS3 protein for DENV-3 showing immunoreactive cells (arrows) in the cerebellar granular layer (G) and in the inflammatory area of cerebrum (H). The insert in G is a negative control from the cerebellum of a non-infected animal. Original magnification: A-B, C (insert), D: x400; C: x200; E-F: x100; G (insert)-H, x1000.